Support for stacked electrode assembly



July 15, 1958 B. CARAS ET AL 2,843,784

SUPPORT FOR sTAcKED ELECTRODE ASSEMBLY Filed May ze, 1955 WILLIAM R. WHEELER BY mao/f A ORNEY ses . 2,843,734 SUPPORT FR STACKED ELECTRUDE ASSEMBLY Bernard Caras, Long Beach, and William R. Wheeler, Wantagh, N. Y., assignors to Sylvania Electric Products Inc., a corporation ot Massachusetts Application May 26, 1955, Serial No. 511,360

Claims. (Cl. 313-256) The present invention relates to an electron tube having a stacked electrode assembly and commonly known as a stacked tube and more particularly to an electron tube wherein the electrode assembly is at least partially supported by the inner leads of the electron tube.

t In the present trend to smaller sizes of electron tubes it has become the practice in manufacturing tube types requiring a high degree of reliability to form the electrodes of various shapes which are adapted to be assembled upon a pair of insulating standards disposed at the extremities of the electrodes. The interelectrode spacings are positively maintained by insulating washers of appropriate thicknesses, adapted to fit over the said standards, and assembled between the individual electrodes.

The assembly of electrodes and washers stacked upon the standards has been secured in place, in one known construction, by means of metallic `rods having stops thereon and inserted through bores provided therefor in the insulating standards. Each stop rested against` a metallic electrode on one side of the electrode assembly, and each rod was insulated from a similar electrode on the opposite side of the assembly by means of an additional insulating washer inserted between the latter electrode and another stop welded to the rod, in order to clamp the assembly of electrodes and washers together upon the insulating standards. t

Due to space limitations and thewsmallness of the stacked assembly, no other support for the electrode assembly (such as dummy pins or the like extending through the insulating standard) is provided save that which is afforded by welding the inner` leads of the electron tube to the respective electrodes in order to establish electrical contact therewith. Due to the shape of the electrodes utilized, it has been necessary to make such welds on the active electrode surfaces at points intermediate the standards of the electrode assembly. The welds in question, which are laboriously effected, frequently result in insecure electrical connections and in distortion of the respective electrodes, because ofthe compactness of the assembly and the manner of support thereof as heretofore described, and, therefore, these welds tend to limit the possible reductions in size of such electrode assemblies. Furthermore, by supporting an electrode assembly at points intermediate the standards, shock energy or vibrations, imparted to the electron tube, are unevenly transmitted via the inner leads, to the active electrode surfaces, thereby causing the electrode surfaces to move relatively to each other. The resultant sudden changes in the interelectrode spacings cause noise and microphonism in the radio circuitry in which such tubes have been utilized. t Although the tendency of such tubes to be microphonic is reduced by welding a resilient metallic ribbon between the active electrode surface and the inner lead, such practice, besides impairing the support afforded by the inner leads to the electrode assembly, does not completely alleviate the problem of noise and microphonism; and, further, the cost of manu- ICC facturing a stacked tube is increased by reason of the additional welding and material required.

Accordingly, it is an object of the instant invention to provide a more compact stacked electrode assembly.

Another object is to decrease the number of welds required in fabricating the stacked tube.

Still Aanother object is to eliminate noise and microphonism from the stacked tube.

A further object is `the elimination of resilient connect ing ribbons utilized to provide electrical contact between the inner leads and the respective members of the stacked electrode assembly.

A still further object is to facilitate the welding of the inner leads of the tube to the respective electrodes of the stacked electrode assembly.

Yet another object is to provide an improved manner of supporting a stacked electrode assembly upon the inner leads of an electron tube.

Still another object is the provision of moreeiiicient clamping means for securing the members of the stacked electrode assembly upon the standards thereof.

Still another object is to provide the outermost electrodes of the assembly with clamping means having an additional means associated therewith for facilitating electrical Contact with the outermost electrodes.

Further objects and advantages of the instant invention will become apparent during the presentation of the ensuing description of a Specific form of the invention. it should be understood, however, that the form is merely exemplary in nature and not limitative of the invention, the invention being limited only as required by the claims.

In the accompanying drawings:

Fig. l is a frontelevational view of an electron tube having its envelope sectioned to show one illustrative stacked electrode assembly mounted in accordance with the invention.

Fig. 2 is a section taken on the line 2.-2 of Fig. l.

Fig. 3 is a left side, elevational view of .Fig l with the glass envelope in section.

Fig. 4 is a right side, elevational View of Fig. 1 with the glass envelope in section.

Fig. 5 is a sectional View taken from line 5 5 of Fig. l and showing the disposition of the inn-er leads ofthe stacked electrode assembly.

Fig. 6 is a top plan View of another illustrative electrode assembly mounted in accordance with the: invention, with the envelope in section.

In accordance with the present invention there is provided an electron tube having a stacked electrode assembly wherein the electrodes are held together by clamping means ailixed to at least two of the electrodes and wherein electrical contacting means are associated with the respective electrodes or clamping means, which contacting means are readily accessible for welding to` the proper inner leads and are mechanically resistant to shock and vibratory energy imparted tothe tube. rl`he electrical contacting means are so situated that mechanical stresses imparted thereto are not transmitted to the active electrode surfaces of the electrode assembly, and when Welded to the inner leads, ellicaceous support for the ,assembly is thus obtained.

Referring tothe drawing, in Figs. l and@ there is shown an electron tube of the stacked electrode variety. The tube comprises a dielectric envelope 1, having a plurality of pins 3 extending therethrough, and a stacked electrode assembly mounted upon the inner leads of thel electron tube. Supported upon the standards 5 of the assembly are a forward anode 7, rear anode 9, forward grid 1l, rear grid 13, and cathode l5. A heating element 16. is inserted into the cathode l5 and is supported by and electrically connected to the inneiuleads 18 (Fig. 5.) bythe connecting ribbon 20. It will be obvious that other arrangements and combinations of electrodes may be utilized. The proper interelectrode spacings between the respective grids and the cathode are maintained by the insulating washers 17 adapted to fit over the insulating standards 5V. Similar washers 19 maintain the necessary spacings between the respective grids and anodes. The electrodes and washers are clamped together upon the standards 5 by the frictional engagement of the anode straps 21 and 23 with the insulating standards.

Each of the anode straps 21 and 23 may be made in two identical but opposing brackets or straps halves, as shown, and welded together at the extensions 25 and 27, respectively, the welds serving additionally to tighten the anode straps about the standards 5. Alternatively, the anode straps 21 and 23 may form initially loosely fitting, continuous loops (not shown) about the standards 5, which loops can be drawn tight by spot welding at the points 26 and 28. As hereinafter more fully pointed out, electrical connections to the anodes 7 and 9 can be effected by attaching inner leads or other connectors to the anode straps 21 and 23 at the extensions 25 and 27, or

alternatively, but less desirably, at the points 26 and 28,

when such extensions or points are welded. It should be understood that the straps 21 and 23 may be formed integrally with the anodes 7 and 9, respectively, by wellknown methods of die-stamping and folding to the de lized in the stacked tube of the invention, which members extend beyond the standards 5 and the spacers 17 and 19 to points where electrical contact can be conveniently made with the inner leads of the electron tube. The stacked assembly is thereby supported on the inner leads at points exten'or to the standards 5 of the assembly, in a manner to be explained in greater detail as this description proceeds.

In order to make electrical contact with the plates 7 and 9, at least one each of the anode straps 21 and 23 is provided with extensions 25 and 27, respectively, which are welded to the inner leads 29 and 31, respectively. In addition to furnishing the necessary electrical connections, the welds serve to secure the anode straps 21 and 23 about the standards 5.

The grids 11 and 13, which may be planar in form, are furnished with integral tabs 33 and 35, respectively, which extended beyond the spacers 17 and 19, whereby the said tabs can be conveniently welded to the inner leads 37 and 39, respectively.

The cathode 15 is supported between the standards 5 through the use of the two cathode supporting loops 41, one aixed to each side of the cathode. The necessity of providing the cathode 15, before assembly, with an additional tab welded directly to the cathode surface for eEecting electrical contact with an inner lead, is obviated by extending the cathode loops 41 beyond the spacers 17, where an easily accessible electrical connection may be made to the connecting ribbon 43 (Fig. 1), which is in turn welded to the trimmed inner lead 4S. Alternatively, the ribbon 43 can be eliminated and the uncut 39 (Fig. 3), which make electrical contact between the respective outer leads indicated generally at 3 and the grid tabs 33 and 35, protruding beyond the spacers 17 and 19 (Fig. 2). The right portion of the electrode assembly is adequately supported by the anode inner leads 29 and 31 (Fig. 4) which make electrical contact between the respective outer leads 3 and the anode straps 21 and 23, which protrude beyond the standard 5.

One manner of distributing and balancing the support afforded the stacked electrode assembly, depicted in Fig. l, by the inner leads thereof, is indicated for illustrative purposes only in Fig. 5 in which the disposition of the grid inner leads 37 and 39 and anode inner leads 29 and 31 is shown.

Another one of many possible electrode arrangements to which the invention may be applied is illustrated in Fig. 6. Supported upon the standards 5 of the assembly are a cathode 47, a first grid 49, a second grid 51, and an anode 53. The cathode 47 is provided with a heating element (not shown) and may be adapted, in a wellknown manner, to emit electrons from only the side facing the remaining electrodes, if desired. Accurate interelectrode spacings are maintained respectively by the insulating washers 55, 57, and 59. The electrodes and washers are clamped together upon the standards 5 by the frictional engagement of the anode straps 23 and the cathode straps 61 with the insulating standards. The structure of the cathode straps 61 is similar to that described heretofore in connection with the anode straps 23 of Figs. 1 to 4. The widths of the straps 23 and 61 respectively, may be varied in accordance with the dimensions of the cathode and anode. The anode straps 23, cathode straps 61, the first grid, and the second grid are provided with extensions 27, 63, 65, and 67, respectively, protruding beyond the insulating washers, and to which electrical connections may be made via the inner leads denoted generally as 69.

It will be readily understood that one or more grids, or none, may be utilized in any of the electrode arrangements of Figs. 1 and 6. It is also apparent that more than one cathode may be used, and where more than one is used, they, desirably, should be suitably shielded one from another.

Thus it is readily apparent that a stacked electrode assembly having all of the electrical connections thereto made exteriorly of the standards, is provided by the nvention. The electrodes may be clamped together on the standards by clamping means associated with at least two of the electrodes and which also may be utilized to make electrical contact with the electrodes.

What is claimed as new is:

l. In combination with the inner leads of an electron tube, an `electrode assembly comprising a pair of insulating standards; a plurality of electrodes assembled upon the standards, said electrodes including a centrally disposed cathode, a first anode spacedly assembled on one side of said cathode, a second anode spacedly assembled on the other side of said cathode, a grid disposed between said cathode and the first anode, and a grid disposed between said cathode and the second anode; a plurality of insulating spacing members assembled on said standards and disposed between said electrodes; engaging means attached to said cathode and said grids and engaging said standards; and clamping means attached to said anodes, engaging said standards and clamping the electrodes and the spacing members together on the standards, said clamping means including a first pair of straps and a second pair of straps, said first pair of straps being attached to the first anode and tightly engaging said standards respectively and said second pair of straps being attached to the second anode and tightly engaging said standards respectively; and individual electrical contacting means on said engaging means and on said clamping means and protruding exteriorly of said spacing members and out of the space between the standards, said contacting means 5 being electrically connected to said inner leads, said inner leads and said contacting means supporting said electrode assembly.

2. An electron device having a base, pins extending through the base and an electrode assembly, said assembly comprising: a pair of spaced parallel insulating rods, a plurality of electrodes having engaging means adapted to engage the rods and assembled on said rods, a plurality of insulating members disposed on said rods between said engaging means, and all of the electrodes engaging the f I' rods having electrical contacting means closely adjacent the rods and on said engaging means and protruding eX- teriorly of said insulating members and out of the space between the rods; and said pins being connected directly to said contacting means.

3. An electron device having a base, pins extending through the base and an electrode assembly, said assembly comprising: a pair of spaced parallel insulating rods, a plurality of electrodes having engaging means adapted to engage the rods and assembled on said rods, a plurality of insulating members disposed on said rods between said engaging means, and all of the electrodes engaging the rods having electrical contacting means closely adjacent the rods and on said engaging means and protruding exteriorly of said insulating members and set out of the space between the rods; and said pins being connected directly to said contacting means, the rods lying in a plane parallel to the base.

4. An electron device having a base, pins extending through the base and an electrode assembly, said assembly comprising: a pair of spaced parallel insulating rods, a plurality of electrodes having engaging means adapted to engage the rods and assembled on said rods, a plurality of insulating members disposed on said rods between said engaging means, and all of the electrodes engaging the rods having electrical contacting means closely adjacent the rods and on said engaging means and protruding exteriorly of said insulating members and out of the space between the rods; and said pins being connected to said contacting means.

5. An electron device having a base, pins extending through the base and an electrode assembly, said assembly comprising: a pair of spaced parallel insulating rods, a plurality of electrodes having engaging means adapted to engage the rods and assembled on said rods, a plurality of insulating members disposed on said rods between said engaging means, and all or the electrodes engaging the rods having electrical contacting means closely adjacent the rods and on said engaging means and protruding exteriorly of said insulating members and out of the space between the rods; said pins being connected to said contacting means, the rods lying in a plane parallel to the base.

References Cited in the iile of this patent UNITED STATES PATENTS 1,844,319 Hatt Feb. 9, 1932 1,956,599 Sperti May 1, 1934 2,111,231 Von Ardenne Mar. 15, 1938 2,436,734 Van Den Bosch Feb. 24, 1948 2,441,792 Brian May 18, 1948 2,463,635 McIntosh Mar. 8, 1949 2,495,618 Warren Jan. 24, 1950 2,503,806 Diggle Apr. 11, 1950 2,660,688 Walsh Nov. 24, 1953 2,713,650 Sears July 19, 1955 

